12v Device: La Crosse AA/AAA Charger
La Crosse BC-700CBP AA/AAA Charger
This charger is awesome because it has an automated battery refresh function that can bring a completely useless NiCd or NiMH back to full working service. This charger can charge or refresh 4 cells at a time, can measure capacity, and generally works great. Now, the down side.. It requires a 3v DC power source, so in order to run this from 12v, you must use a DC/DC buck converter. I made one for this charger and it works great from 12v.